Fire extinguisher



Jan. 10, 1939. I G, SCHAAF 2,143,635.

FIRE EXTINGUISHER Filed June 6, 1936 I INVENTOR flea gge 5c Zm-af BYfig? Patented Jan. 10, 1939 UNITED STATES PATENT OFFICE 12 Claims.

This invention relates to fire extinguishers of the type which employ aliquid carbon dioxide stored in a container under pressure and moreparticularly to the method and apparatus for 5 handling and dischargingthe liquid to expand into a gas and to form a snow.

My present invention provides a device for efiectively dischargingcarbon dioxide from a high pressure by expanding a stream of said carbon10 dioxide through an expansion chamber which is kept at low temperatureto break up and retard said stream and produce snow.

Various devices have been produced to use carbon dioxide as a fireextinguishing medium and 15 in such use to produce a snow as themost-effective form to blanket a fire. Most of these devices employ amethod of carrying the fluid at a high pressure to a restriction at thepoint of emergence which produces a high velocity of the issuing streamat said point.

My method and apparatus for discharging carbon dioxide from a containerholding said carbon dioxide under a high pressure is to partly expandthe dioxide in a conduit which is in the container 25 leading from nearthe bottom to the top thereof and so to convey the fluid at a reducedpressure but liquid form through a passage of uniform diameter to anexpansion chamber which is maintained at a low temperature and toprevent 30 the interchange of heat between the outside air and the fluidin its passage by insulating the passage ways from the container to adischarge opening into the air.

This is accomplished by introducing the liquid 35 into the lower end ofa conduit near the bottom of the container through the smallest passagein the discharge system, successively enlarging the passage in saidconduit toward the top to partly expand the liquid in said conduit,conveying the 40 liquid at a reduced pressure through a passage ofuniform diameter which is insulated, and then breaking up the liquid byexpanding and spraying it in a chamber surrounding the bottom of thecontainer which is a region. of low temperature 45 and preserving thislow temperature by insulating the said chamber. The fluid passages andexpansion chamber are calculated to expand the fluid to a point wherethe pressure at the discharge opening into the atmosphere will propel 50the issuing stream the distance necessary to blanket a fire from a selfcontained hand apparatus.

An object of the invention is to provide a self contained hand fireextinguisher with means for 55 conveying and directing a stream ofcarbon dioxide gas and snow from an expansion chamber near the bottom orthe container into the air.

' Another object of the invention is to provide a fire extinguisher witha housing to inclose the bottom of a'tank of carbon dioxide as an ex- 5-pansion chamber in which the discharging carbon dioxide is kept at alow temperature by the cooling of said tank during discharge.

Another object is to provide a self contained fire extinguisher in whicha tank is inclosed in an expansion chamber housing and which can bereadily disconnected to replace a partly discharged or empty tank with afull tank and so provide a replaceable part to constantly main tain theextinguisher ready for use.

Another object is to provide a fire extinguisher with the smallestaperture at the beginning of the discharge system to reduce the pressureto, and through an expansion chamber; to keep the expanding carbondioxide at a low temperature and constantly slow up the movement tothe". point of exit from the chamber and to insulate the dischargesystem.

With the foregoing and other objects in view which will appear as thedescription proceeds, the invention consists in certain features ofnovelty in the construction, combination and arrangement of parts bywhich the said objects axe .attained, the invention being moreparticularly pointed out in the claims.

In the accompanying drawing:

Figure 1 is a side elevation, mostly in section, of a container with itshousing and connections which constitute a fire extinguisher embodyingmy invention.

Fig. 2 is a top or plan view of the fire extinguisher.

Fig. 3 is a sectional plan through the housing and container in twoportions, one portion on line 3-3a--3b of Fig. 1 (also indicated on Fig.3) 40 to show the expansion chamber and the other portion online 3-30-30of Fig. 1 (also indicated on Fig. 3) to show the air insulation.

Fig. 4 is a side elevation of the bottom portion of the housing showingthe discharge opening and the discharge passages in dotted lines leadingto said opening.

In the drawing, l is a storage tank or container to hold a charge ofliquid carbon dioxide 2 under pressure. The L shaped plug 3 is screwedinto the top of container I and has a valve which can be represented byhandle I for controlling the passage 5 in plug 3 to the outside pipe 6which is preferably a copper tube. Screwed into the bottom of plug 3 isa discharge conduit 1 so which extends to near the bottom of containeri. The conduit I has a small passage 8 at the bottom, with a .graduatedopening into said passage 8, and a passage which increases in size 'fromsaid bottom passage 8 by successive steps as 9, I0, I l and I2 to thetop as shown. The passage I2 at the top of conduit I is the same size asthe passage 5 in plug 3 and passage 26 in tube 6. For example if thesize of the passage I2 at the top is A6" the bottom passage 8 may be 6",passage 9 may be 55 passage I may be 34;" and passage ll may be 952".The lengths of different sized passages 8 to I2 also proportionatelyvary somewhat as shown. I do not limit myself to these dimensions butgive them as illustrative of the successive steps of enlargement of thepassage in the conduit 1 and as a convenient method of forming saidpassage.

I3 is a housing, rectangular in vertical section as shown in Fig. 1 andcircular in form as shown by its plan in Figs. 2 and 3. The verticalside wall I4 ofthe housing I3 is in the form of a circular shell withbottom I and top I6. An inner shell with a vertical side wall I!parallel to the outer wall I4 is located between the bottom I5 and topI6. Inner shell I! is of a size to accomodate a tank I, the lower end ofwhich is inclosed as shown in Fig. 1. Inner shell I1 is locatedeccentric with outer shell I4 to inclose an eccentric air space I8between them.

As a means of fastening the tank I into the housing I3 a, verticalflange I9 is provided on the top I6 of housing I3. Flange I9 is split atand separated from the top I6 for a short distance as 2| on each side ofsaid split 20 and by means of lugs 22 and bolt 23 the tank I is clampedinto the housing I3.

Connected to the inner shell I'I near itstop and on the side locatednearest to the outer shell I4 is a nozzle 24 extending up diagonally tothe top I 6 to which said nozzle is also connected. The lower end oftube 6 is shown connected by threads into the top of the nozzle 24 andat the upper end to plug 3 by means of a union 25. The passage 21 in thetop of nozzle 24 is the same size as the passage 26 in the tube 6(Fig. 1) but increases in size as it approaches the inner shell IT byspreading out horizontally (Fig. 3).

Near the bottom of housing I3 and on the opposite side from nozzle 24 isa discharge cone 28 having a discharge opening 29. Running diagonallydownward from the nozzle 24 to the discharge cone 28 and extending onopposite sides of the tank I is a horn 30 inclosing an expansion chamber3|. The portion of the horn 30 on each side of the tank I is complete initself but carries only one half of the stream from the nozzle to thedischarge cone so the portions on each side of the tank might beconsidered as one horn divided by the tank I. The horn is built in as aportion of the inner shell l1, and being shown rectangular in shape, oneside is open and the open side is closed by the side of the tank I. Thetaper of the horn 30 is such as to form an expansion chamber 3| throughwhich a stream will expand from the nozzle 24 to the discharge opening29.

The tank I is insulated by the air in the air space I8 and the horn 30is also insulated as it is in said air space I8. A boss 32 on thehousing I3 surrounds, but is spaced fromflthe nozzle 24 and insulatessaid nozzle by air in said housing I3. The tube 6 is insulated by air inthe casing 33 surrounding it as shown in Fig, 1.

35 is a lower handle attached to the side wall l4 of the housing l3 andlocated as shown in Figs. 1, 2 and 3. The upper end of tube 6 and itscasing 33 are curved at 34 to form an upper handle and together withlower handle 35 form means to carry and hold tank I and housing I3 todirect a stream of discharged gas and snow from cone 28 onto a fire.

The insulating of the tube 6 prevents the interchange of heat betweenthe outside air and the carbon dioxide while passing from the tank I tothe expansion chamber 3! in the horn so and to maintain the carbondioxide in its liquid state.

When the tank I is completely discharged it is disconnected from thetube 6 by unscrewing the union and loosening the nut on the clampingbolt I9 and the tank I then lifted from the housing l3 to be replaced bya full tank.

The operation of my fire extinguisher consists in opening the valve 4 torelease the carbon dioxide 2 which is confined in tank I under apressure which is normally about 750 pounds per square inch. The liquid2 traverses the passages 8, 9, II], I I and I2 in the conduit I, thepassage 5 in the plug 3, the passage 26 in tube 6, the expansion chamber3! in horn and is discharged into the air through the opening 29 in thedischarge cone 28.

A partial drop in pressure and some expansion will occur in the carbondioxide liquid as it passes through the conduit I from the passage 8 atthe bottom to passage I2 at the top and also a slowing down of thestream from the passage 8 as it expands. The speed of the stream throughthe uniform passages l2, 5, 26 and 24 will be uniform and withpractically no expansion until it reaches passage 21 in the lower partof nozzle 24 where it suddenly expands to spray the liquid into andthrough the expansion chamber 3i of the horn 30 with a consequentslowing down to the discharge opening 29.

The breaking up of the stream of discharging carbon dioxide liquid as itissues from the nozzle 24 to strike against the tank I separating itinto two streams and expanding it from the said nozzle to the dischargeopening 29 forms a gas and snow. There being no restriction at the pointwhere the liquid is broken up and sprayed to form snow but an expansionchamber which increases rapidly in size the snow which is formed isreadily discharged without piling up to clog the passage. The partalexpansion of the liquid 2 in the conduit I cools the tank I and helps tomaintain the zone of low temperature in the horn 30 which is induced bythe expansion of the stream in said horn.

Having thus described my invention, I claim:

1. A fire extinguishing apparatus including a container for carbondioxide under pressure, a conduit in said container having a passageincreasing in size from the bottom of said conduit for expanding thefluid, an expansion chamber surrounding said container, means to form anair chamber about said expansion chamber, means to convey the filuidfrom said conduit to said expansion chamber through a passage of uniformdiameter, and a discharge nozzle from said expansion chamber.

2. A fire extinguishing apparatus including a container for carbondioxide under pressure, an expansion chamber surrounding said container,a nozzle to discharge the fluid from said expansion chamber, means toinsulate said expansion chamber and means to convey the fluid from nearthe bottom of said container to said expansion chamber whereby the fluidentering said expansion chamber will separate and fiow in oppositedirections around said container to reunite before discharge from saidnozzle.

3. A portable fire extinguishing apparatus including a container forcarbon dioxide under pressure, an expansion chamber surrounding saidcontainer, a. nozzle to discharge the fluid from said expansion chamber,passage means from near the bottom of said container to said expansionchamber said passage means including a conduit in said container and anoutside tube connecting the conduit passage with the expansion chamberand an upper and a lower handle for carrying and directing a stream offluid from said apparatus onto a. fire, one of said handles formed fromsaid outside tube.

4. A portable fire extinguishing apparatus including a container forcarbon dioxide under pressure, an expansion chamber surrounding thelower part of said container, a nozzle to discharge the fiuid from nearthe bottom of said expansion chamber and passage means from near thebottom of said container to near the top of said expansion chamber, saidpassage means ineluding an outside tube from the top of said containerto said expansion chamber and form- 'ingahandle to said apparatus.

5. A portable fire extinguishing apparatus including a container forcarbon dioxide under pressure, an expansion chamber surrounding thelower part of said container, a nozzle to discharge the fluid from nearthe bottom of said expansion chamber and passage means from near thebottom of said container to near the top said expansion chamber, saidpassage means including an outside tube from the top of said containerand connected to said expansion chamber "6n the side op to saiddischarge nmle' 6. In a. portable fire extinguishing apparatus 40 forholding a fire extinguishing fluid liquefied under pressure and expandedin said apparatus to a low pressure to a nozzle and to discharge thefluid into the atmosphere through the nozzle at a low velocity, thecombination of a container for carbon dioxide, a plug in the top or saidcontainer, a valve in said plug, an expansion chamber eccentricallysurrounding the lower part of said container, a discharge nozzle nearthe bottom of said expansion chamber, passage means from near the bottomof said container to near the top of said expansion chamber andcontrolled by said plug valve, said passage means including a conduit insaid container and having a e increasing in size toward said plug and atube from said plug to said expansion chamber, means to insulate saidtube and means to insulate said expansion chamber.-

7. A fire extinguishing apparatus comprising a container for carbondioxide under pressure and a discharge system for said container andhaving a eway increasing in successive stages from the opening into saiddischarge system to the discharge opening into the atmosphere, saiddischarge system including a conduit in said container extending fromthe top to near the bottom of said container, an expansion chamber, adischarge nozzle, and connecting passage means between said conduit andsaid nozzle, said expansion chamber located adjacent to said nozzle atthe discharge end of said system.

8. A fire extinguishing apparatus including a container for liquidcarbon dioxide under pressure, a conduit in said container having apassage increasing in. size by successive steps from near the bottom ofsaid conduit, a nozzle and connecting passage means between said conduitand said nozzle, said conduit passage so proportioned as to maintain thecarbon dioxide in liquid form while passing therethrough.

9. A fire extinguishing apparatus including a container for carbondioxide under pressure, a conduit in said container having a passageincreasing in diameter from one to four times toward its outlet topartly reduce the pressure of the fluid, an expansion chamber, meanshaving a uniform diameter to convey the fluid from said conduit to saidexpansion chamber and a discharge nozzle from said expansion chamberwhereby the fluid is discharged into the atmos-- phere from the zone ofgreatest expansion.

10. A fire extinguishing apparatus including a container for carbondioxide under pressure and a discharge system for expanding andconveying the fiuid to the atmosphere at a low pressure, said dischargesystem consisting of an expansion chamber, a discharge nozzle from saidexpansion chamber, connecting passage means from said container to saidexpansion chamber and means to insulate said passage means, saidinsulating means including a casing having closed ends, said casingconforming to the shape of said connecting passage means and spacedtherefrom.

11. A fire extinguishing apparatus including a container for carbondioxide under pressure, a

conduit in said container, an expansion chamber surrounding saidcontainer, a discharge nozzle from said expansion chamber, passage meansto convey the fluid from said conduit to said expansion (namber, a valvein said passage means, and means to insulate said passage means.

12. A fire extinguishing apparatus comprising a container for liquidcarbon dioxide under pressure and a discharge system for said containerand having a passageway increasing in successive stages from the openinginto said discharge system to the discharge opening into the atmosphere,said discharge system including a conduit in said container extendingfrom said container top toward the bottom and having a passageincreasing in diameter near'its inlet end from one to four times topartly reduce the liquid pressure, a valve at the top of said container,a born, a discharge nozzle from said horn. and a tube from said valve tosaid horn, said conduit, valve and tube having a continuous passage of auniform diameter from the largest diameter in said conduit to said horn.

GEORGE BCHAAI".

